This is Hockey, not Basketball. They are 2 VASTLY different sports. In basketball a single superstar can carry the team to a championship. That doesn't happen in hockey. If it did, Ovechkin would have more than 1 cup. Further, If McDavid would make or break the team, then how come the 'hawks plowed through him and Draisatl? I mean...it's the 'hawks--one of if not the worst D in the league and a cold, post-COVID Crawford made the Oil with 2 of the best players in the league look bad.
So of course we'd take a defensive player over McDavid. We know hockey and how it works.
Adding McDavid would give something like 1 extra goal every 2 games--he's about a .5GPG player. What he won't address is the fact that the defense leaks chances like a sieve. Hell, Kane has better defense numbers than McDavid! So for an extra goal every 2 games or so, the D would still leak like a sieve.
Hedman, Coturier, Stone, etc.would actually help getting the shots and chances down to give the goalies a chance to actually breathe, which would lower the GA enough that Kane, Toews, Koob, Saad, etc. could actually outscore opponents and might actually up the puck possession a bit since the 'hawks wouldn't be hemmed into their own zone for epochs like they have been.